Manufacture of butt and lap welded tubes



Feb.-4,' 1930. a p, w, CHlsHQLM I 1,745,741

- l IIANUFACTURE OF BUTT -AND LAP WELDED TUBES v Filed yom.' i1. 1926- 4 sheets-sheet 1 y 4, 1930. D, w, CHlsHOLM y 1,745,741.

HANUFACTURE 0F BUTT AND LAP WELDED lTUBES Filed Oct. 11. 1926 4 Smets-Sheet 2 Feb. 4, 1 930. D. w. cl-nsHoLM l1,745,741

. MANUFACTURE OF BUTT AND LAP WELDED TUBESv Filed Oct. l1, 1926 4-Sheets-Shee-t 3 Feb. 4, 1930. I D, w, CHlsHOLM l,.'z745 ,74l Y MANUFACTURE OF BUTT AND LAP WELDED TUBES Filed oct. 11, 1926 4 sheets-*Sheet 4 Patented` Feb.l 4, 41930 UNITED STATES PATENT OFFICE `DOUGLAS WHIMSTER CHISHOLM, F GLASGOW, SCOTLAND, ASSIGNOR T0 THE BIRCH- FIELD ENGINEERING COMPANY LIMITED, 0F ICARDIFF, WALES v MANUFAGTURE `or BUTT AND LAP WELDED TUBES Application filed October 11, 1926, Serial No. 140,820, andp in Great Britain February 2, 1926.

This invention relates to the manufacture of welded tubes by tube welding machinery of the type wherein a metal strip heated in a furnace is drawn through a bell or die and 6 ater a suitable welding gas has been applied p the edges of the strip, the edges are closed and welded together by the action of rolls and (or) other suitable devices. y

According to one of the features of thepres- 10 ent invention I -proyide welding machlnery lmay or may of the type specified comprising relatively movable closing rolls, a divided welding bell or die whose parts are separable, and automatically acting means whereby the rolls and the parts lof the bell or die can be simultaneously brought together into operative position or moved apart out ooperative position. The saidvmeans may comprise automatic control gear adapted to be actuated in accordance with the operation of the draw bench chain, and may be such that the speed of separation and approach of the rolls and the parts of the bell or die is gradually reduced Y before the fiend of said separation or ap proach. C

According to another feature of the "invention I provide 'tube welding machinery, of`

the-type specified, lcomprising means (which not ,be automatic in action) whereby the" rolls and the die parts can be simultaneously brought together into @or moved` apart out of operative position, and means whereby one of the parts ofthe die is changed automatically (so as to present a fresh surface) -each time the parts, after separation, are brought. together again. .ThgJ

last 'mentioned means may comprise an ar-l J rangement of half dies adapted forl angular movement about a horizontal axis and adapted to be brought successively into operative vrelationship wltha common fixed half die by automatic .means which operates when the closing rolls v.are separated andthen brought togethenl (I Y 'According to a further feature of the invention provide an auxiliary chamber for welding ga's, located between the source of gas and its point or points of Means may also'be provided whereby both machine showing the automatic gear for raising and lowering the upper closing roll and the upper die member, the two latter being shown raised.

Fig. 2 is a side view corresponding to Fig. 1 except that the upper closing roll and upper die member are shown lowered.

Fig. 3 is an enlarged detail elevation (taken from the rear)` of part of the machine shown in Fig. 1. i

Fig. 3a is a detail view of parts in Fig. 1.

Fig. 4 is a detail `'view similar to Fig. 3, except that the operating members are shown in a different position. v

Figure 4a is a fragmentary section of the trip gear showing the parts in neutral position. f

Figure 4b is a view similar to Figure 4a but Nshowing the' parts in their next succeeding position.

Fig. 5 is a plan view (with the top plate of the bracket 23 removed) of the detail shown in the rear elevation, Fig. 4.

Fig. 6 is an enlarged detail View in side sectional elevation of a modication comprising the means for automatically changing the upper die member.

Fig. 7 is a front view (toa somewhat larger hscale) of the arrangement shown in Fig. 6.

Referring to'v the drawings movable upper housing 1 and a fixed lower housing 2, the upper housing carrying the upper closing roll 3 and the upper half 5 of the welding bll of themachine, and the lower housing 2 carrying the lower closing roll 4 and the lower half 6 of the bell. The closing rolls 3, 4 and the upper and lower halves 5, 6 ofthe welding bell meet'in operative relationship when the upper and lower housings 1, '2 are together."

For raising and lowering the upper housing-1, twovhydraulic rams comprlsing cylin ders 7, 8` are provided. These cylinders are On the tube welding machine is a vertically f A connecting rods 10 attached at their lower ends to the said upper housing 1 and at their upper ends to a cross head 1l carried by the top end of the said lifting ram plunger 7 D Referring to the automatic control gear for the raisingl and .lowering of the upper housing, it will be observed from Figs. 1 and 2, that a valve -12 is mounted on the column 9 supporting the hydraulic ram cylinders 7 and 8. This valve isof the two wa type, being in communication with the pipe 13 leading to the lowerv cylinder 8, with ,the exhaust pipe 14, and with the high pressure supply pipe 15. through an elbow Jointvl an a branch pipe 15". The said valve l2 may thus place the lower ram cylinder 8 in communication wlth either the high` pressure supply pipe 15` orthe exhaust pipe 14.. The

upper cylmder 7 normally remains in c011- stant communication with the supply pipe 15, the relative surface areas of thetwo ram\ plungers 7 and 8? being such that when, as required, the pressure iuid'is admitted to th lower ram plunger 8, the excess of pressure on the said lower (and larger) ram plunger 8a over the upper (and smaller) -raii plunger 7'L is suicient to lower the upper housing 1. Of course', when the -lower ram cylinder 8 is opened by 'means of the valve 12 to Vthe` exhaust pipe 14vthe pressure in the-upper cylinder 7 causes lthe said upper housing 1 ,to rise. In orderj that the opening and closing of the valve 12Vmay be'eifect'ed automatically the control gear hereinafter to be described isrovided n the spindle of the valve l2, a lever 16 is fixed so that by turning the said lever upwards and downwards from the horizontal position, shownlinV full lines Figs. 1 and 2,

the cylinder 8 of the lower ram can be placed g in communication with 'the' `highV pressure supply pi e 15 (as shownin chaindotted lines in Fig. 1) or, the exhaust pipe 14 (as shown in chain dottedlines in Figi2) respectively. -The end of the said valve lever 16 remote from the hydraulic rams7, 8 is connected to the arm of a bell-crank 1 7 by a rod' 18. The other arm of the said crank 17 is connectedby a-link 19 to a crank 20 (not shown in Fi 1 or- 2 but appearing in the detail view*- ig. 3** and in the plan view Fig. -5

l'which latter 4corresponds to the partly sectioned'enlarged rear elevation Fig. 4). l The is fixed. upon a spindlel21 at dthe'reofl remote from the crank22.

The` spindle 21 is carried by a bracket-23 bolted to the draw-bench D. On the free end 'of the crank 22 a roller 24 is, mounted, the

said roller normally projecting into the path of a cup 25 (see'Fig. 1) carried., by lthe draw chain E. On the spindle 21 between the crank 22 and the crank 20, a tri llever 26 1s secured (see Fi s. 3, 4 and 5). 26 is adapted t6 co-operate with a trip 27 and a tripper 28 for the urpose of operating the valve 1ever\16,(see igs. 1 and 2) so as to raise thei upper housing 1,' as will be hereinafter descri ed.

his lever The tripper 28 (see Figs. 3, 4 and 5) is rotatably mounted on a pin. 29,`carried by the bracket 23, and is formed with a rearwardly projecting lu 30, which is adapted to move between two xed'stops 31, 32. At" its outer en'd the tripper 28 is formed with a nosepiece 33 projecting sideways at right angles to the. piane of the tripper. (as shown in Fig. 5). On its under surfacethetripper 28 :sov

is formed with anenlargement 34 for the The s'aid hook shaped end ofthe link 27 is* formed moreover with a notch 38, of which the shape corresponds to that of Yth'enose piece 33 on the tripper 28. At the to end Aof the trip lever, 26 a lug, 39 is forme projecting sideways from the plane of the said lever 26.

As will be seen from Fig.'5 of the enlarge- 'I nient 34 o n theV tripper 28 is in the same plane as the lugy 39 on the trip lever 26, whilst the nose piece 33 on thel tripper 28is copla'ner with thetrip link 27.

` The neutral condition of the apparatus is Y shown in Fig. 1, the upper housing 1 beingA elevated so that the apparatus is in` condition for an attendant to thrust the usual tongs endwise between the separated housing members 1 and 2,'and engage the tongs-with` aheated strip in the furnace and then drop the ton s down u on the draw bench'in position `to e engage by the cup 25 of the draw chain E. -The neutral condition of the trip gear is shown in Fig. 4, the trip lever 26 being in a substantially upright position in parallelism with the crank 22, and the trip link 27 disengaged from the trip lever 26. -It will here benoted that the crank 22 and the trip lever 26 are carried by the rock-bar 21 at substantially the same angular relationthereto, and therefore the trip lever 26 moves with and in the samedirection as the crank 22.

On the pin 35 carrying the trip link 27, a link40 is also mounted. This link 40 at its outer end is connected by a rocking lever- 41,

is journalled in a 41" and a rod 42 to a. crank 43 secured to an upright shaft 44 Fig". 1). The said shaft 44 'aring 45 on the bracket 23 and its upper end carries a kick-lever 46 which normally projects into the path of the draw chain E (which passes over thecrank 22 shown in Fig. 5) so that when the cup 25 (see Fig. 1) arrives at the said lever 46, the latter 4is forced (to the left in Fig. 2) out of `the path of the draw chain E. If no tube has been connected by the grippingk tongs to the draw chain E, the kick lever 46 thereafter resumes its normal position as constrained by the spring 47 (broken away for the sake of clearness in Fig. 5) attached to the crank 48 on the upright shaft 44. In the event, however, of a tube being drawn through the die (5, 6) and closing rolls (3, 4) the said kicklever 46 is held over in its new position, until by engagement of the tube with the kick-lever the inner end of the welded tube has vpassed and escaped from the kick-lever, after which thekick-lever resumes its normal lposition as before. 1 l

The link -connecting the trip link 27 and K rocking lever 41 is provided with a leaf spring 49, adapted to press down upon a small rib 50 formed on the upper surface of the trip link 27. vThe said trip link 27 is prevented from falling below the horizontal position illusheel portion 51 on the adjacent upright face of the link 40. i

1n order that the mechanism described in the foregoing may be clearly understood, the operation thereof in the course of one complete cycle of the drawV chain E will now be described I.Assuming the upper housing 1 with the upper die block 5 and upper closing roll 3 is already raised, and the trip gear in its neutral condition as shown in Fig. 4a it will be seen from Fig. 1 that the approach of the cup 25 on the draw chain towards the crank 22 will' ultimately cause the said crank "to rotate and, throughspindle 21, crank 2O and link 19,- rock the bell crank 17 in an anti-clockwise sense about its pivot thereby drawing down the rod 18 and turning-the valve lever 16 in a clockwise direction, all as shown in chain Y. dotted plines .inFig 1. The said movement of the valve lever 16 causesthe lower `ram cylinder- 8 to be placed in communication with the high pressure supply pipe 15, whereby, as before described, the upper housing 1 (with upper roll 3 and top half die 5) iscaused to descend. n. Therotationy of the rocki' bar 21 by theaction of-the eup 25 of course causes the trip lever 26 to move. to the right from its neutral position in Fig. 4 to the 4position in Fig. 4". This movement'of the ,trip v lever 26 is not interfered with by the tripper 28, vbecause the under surface of lsaid tripper'is'in 4the shapeof an arc of which the center' corresponds to the axis of the shaft 21 on which the trip lever 26 is mounted so that the part 26 may be moved from its position in Figure 4a to the position in Figure 4b without raising the tripper 28, as the latering 1, comes into contact with the Valve lever,

16. Thereafter the continued descent of the finger 52 gradually causes the valve lever 16 to be returned to the normal horizontal position, as shown in full lines in Fig. 2, whichposition'is assumed when the die parts and rolls are in operative relationship. In this position the valve 12 is closed both to supply pipe 15 and exhaust pipe 14; therefore the housing 1 remains at rest and upon the lower housing 2. Simultaneously with the closing of the valve 12 the cranks 17 and 22 are returned to their neutral positions shown in' full lines in Figs'l and 2, by the upward movement of the rod 18, which swings the bell crank 17 and the crank 22 to the right resulting in the turning of the rock-'bar 21, which in turn swings the trip lever 26 from its position in Fig. 4b back to its neutral osition in Fig. 4a. The gradual closure o the valve 12 ensures that the speed of the roll 3 and the half die 5 is gradually reduced before the end of the lowering movement.

f As the cup 25 on the draw chain E continues its movement beyond the crank 22 and overthe usual chain sprocket wheel d, it eventually comes intoA contact with the kick-lever 46, which is thereby forced over to the position shown in full lines in Figs. 2 and 3. Such movement of the kick-lever 46 results -in the trip link 27 being thrust forward, from' its neutral position shown in Figj4 to its position shown in Fig. 3, so that the hook shaped end portion thereof rides over the top end of the trip lever 26 and, by reason of the leaf spring 49, engages the said top end of the said trip lever 26 as shown in Fig. 3. From` the same figures of thel drawings it will be observed that when the trip lever 26 is in the neutral position, the-lug 39 on the said lever abuts against the enlargement-340m the tripper 28, so that the nose piece 33 on the' tripper is held upwards out of the path of the notch 28 on the hook shaped end of the trip link 27.

Should no tube be drawn through the die and closing rolls, the movement of the cup 25 past the kick-lever 46 will reslt in the latter being returned to its normal 'position by ,means ofthe spring' 47 as hereinafter referred to. Such return movement causes the trip lever 26 te be drawn backwards by the trip link l27 from the position of Fig. 3 to the 1 position of Fig. 4, thereby rocking the rockbar 21 so that fthe bell-crankl is rotated in a clockwise sense and thereby pushes up the rod 18 attached tothe'end of the'v'alve lever 16, all as shown in chainvdotted lines in Fig.

2. This movement of the said-valve lever 16 results in lthe llower ram cylinder 8 being placedv in communication with the exhaust Ipipe 1-4 with the consequent raising-'of the upper housing 1 as before explained:

Normally, that is, when a'tube is drawn out of a furnace and through the die and rolls by the drawn chain E, it keeps the kick lever 46 open and while it remains in this position i I the automatic upward movement of the-upper tial device. Y

' operative relation with the stip and is held the strip in a potential condition while'the strip is .moving through the apparatus..

Furthermore the potential device is associated with the gas controlling meansso as to actuate the same to effect closing of the gas conduit when the strip'passes outl of cooperation -with the lever- '46 and therebyreleases the poten- 'The extreme position .of the trip-lever 26 and trip link 27 corresponding to the full-exhaust position of thel valve 12 is showm in Figs4a'nd5. '.f As the upper housing 1, continues its ascent the linger 53 on'one of the rods 10 connecting the said housing 1 and the upper ram plunger 7*" comes intocontact with the valve lever 16 and moves the latter in a clockwise `sense to the positionfulllines in Fig. 1.v The p eiect of this movement of the valve lever 16 ijs to close the Vvalve 12 gradually'both from the supply pipe 15 fand exhaust pipe Vi4 andl thereby reduce 'and linally bring Vto zero the speed of the v.ascending roll 3 and half die 5.

--At the-same time, the bell crank 17 is ro-v tated, by'thero'd' 18, in an anti-clockwif e direction so as to reset ,the crank 22 and tulp lever 26 to their neutral position. In` this position th, tripper'28 is thrust upwards, whilst the link 27 springs backward to the position shownv in Fig. 4a.

When -the foregoing movements have been completed, the' cup 25 lwill be travelling along below the draw bench I) towards the crank'22'. Thus the complete' cycle of 0perations'entailed in the automatic lowering and raisingof the upper housing 1 has been completed, and a new cycle ensues.

Referring to the modilication4 of the invention shown in Figs. 6 and 7 Thelowr closing roll 4 is driven by means of an electric motor 54 through gearing 55,

- 56 shaft573and gearin 58, 59. The upper roll 3'receive`s its drive rom a sprocket wheel 60 through a chain 61 which passes `over the sprocket wheel 62 (see Fig. 6) on the shaft of the upper roll 3. The wheel 60 is mounted I on a countrslaft 63 which is driven by a the shaft 57 (the wheel 65 being situated'behind the gear wheel 59 in the view shown in chain 64 passing over a sprocket wheel 65 on Figs` 6). This arrangement obviates the disv advantages such as possible jarring of the gear teeth when the upper roll is lowered, attendant upon a direct 'drive between the sprocket wheels 59 and 62. In the preseiit arrangement, the upper roll 3, as lwell' as the lower roll4, is kept in constant rotation, vwhether the rolls are together or apart. The countershaft 63 is adjustable vertically by means of the screw 66 supported by the threaded bracket 66, so that the tension of the chains 61, 64 may be varied.

On the upperhous'ing l, a central boss 68 is formed, integral with the front wall l", and on this boss 68. a multiplel die block 5 of subs'tantially-t square outlineV (see the enlarged view, Fig. v7) is rotatably mounted. The die block 5 is held in placeon the boss 68 by means block- 5 is formed with'a large concave tapering depression 70.,- as shown, the depression in each case being flared Aoutwardly towards the front of the bloXck and constricted to substantially'semi-cylindrical shape towards the rear. In this manner each side of the block 5 virtually constitutes the upper half of a skelping die, of which thelower .half (6) is formed integral with thelowerhousing 2. It will. be observed that the flared end-of each depression 70 is not coaxial with the constrictedl semi-cylindrical end thereof, so that the lskelping of the strip bythe die is eiiected smoothly and -gradually," without abrupt of-a bolt 69 andwasher 69. .Each side of the .i

change in the curvature of the strip, the edges ,thereof being first bent downwards and then the strip finally given its open-jointed .tube

shape as it passes through vthe rear part of the die. v

Adjacent to the multiple die block 5, a lever 7 1 (Fig. 7) 1s arranged, this lever being piv- .oted at itslower end on a bolt 72 on the lower houslng 2 and being constrained by a weight 73 to lean o ver towards the axis of the dieblock. On the front of theblock 5', four pins 7 4*l and 7 4d are arranged, these ,pins being disposed o n the two diagonalsyof the block at i equal dlstancesfron one another as shown.

jIn virtue of the weight 73, the lever 71 rests aglainst one of the pins (74a in Fig, 7) so that w en the upper'housing 1 with the die block t 5- is raised, the vpin 74, and, subsequently, the pin 7 4"", slide up the contiguous edge ofthe lever 71, the upward movement of the hous- 1ing 1 being such that the latteri pin 74h, rises above the step 75 ofthe lever '71,`which lever,

`in virtue of the weightl 7 3, thereupon moves inwards towards the axis'ofvthe block 5 'and pro3ects the step 'Z 5 beneath the said pin 7 4".

' Thus, when the housing 1 is lowered again, .130

vthe pin 74b is arrested by the. projecting-'step 75, whereupon the die block is partially ro-` tated about its boss 68. When the block has almost completed a quarter of a turn, the pin 74c on the die block 5 comes against the en# larged part 76 ofthe edgeof the lever 71 and thereby knocks the said lever 71 sideways and releases the pin 7a from the step 75. The continued downward movement of the housing 1 results in the multiple die block 5 being 10' brought down into operative relationship with the lower half 6 of the die, the said block, in the course of its upward and downward movement, having been rotated automatically through 90. The sideways movement ofthe lever 71 away from the die block 5 is limited by a stop 71i carried upon the upper housing 1 by the bracket 711.l

On the lower half 6 of the die a bar H Y (Fig. 6) is provided, the said bar having attached to its smaller end (Fig. 6) a fixed mandrel F1. 1 To press the fixed mandrel F1 down upon the interior of the edges of the skelped strip as it` passes through the rolls, a depending strap 77 (Fig. 7) is em loyed, this strap beingy connected to a bar 8, one end ofv which is pivoted to a bolt 79 carried by the side member 2a of the lower housing 2 and the other end of which extends through a slot 3 78a in the other side member 2a between'a fixed lug 80 and a stop bolt 81. A wedge 82 is adapted to be inserted between the fixed lug 80 and the adjacent end ofv the bar 78 and is adapted to be driven between the said parts suiiiciently far tobring the said end down on the stop bolt 81 which is set so that, when the bar rests thereon, a predetermined pressure is brought rto bear on the interior of the edges of the strip as it passes through the rolls.

A loose mandrel F2 is supported by the wall 2b of the lower housing 2, a collar 83. being formed on the adjacent end of the mandrel F2 and a corresponding seat 84; belng formed on the upper edge of the wall 2b. v

Within lthe frame A of the welding machine, asv shown in Fig'. 6, a chamber 85 1s provided for the supply lof welding gas, the gas being led by a pipe 86 to the said chamber 59 from a su ply providednearby. Thewelding gas or example, oxygen) is applied to the skelped edges of the strip at two places namely,where the edges pass through the) guide G, and in advance of the said 1de,

5 5 just before the pass of the rolls 3, 4. n the from thechamv first place the oxygen Pases vtubes from metal strips, tube Weldin ber 85 by way of thevpipe 87 which, in the 'construction illustrated is led up the front of the housing 2 and .thence alongb'elow the. 60 bar H to the mandrel F2 and guide G.' A 1second pipe 87a is led from the c hamber 85 to a point in advance of the gugde G, the nozzle of this pipe 87 belng close tothepass between the rolls 3 and 4.. -The chamber 85 ensures a more regular. supply and almere constant pre ure of oxygen at the nozzle of the pipes 87,587,

In Figs. 1 and 2 means for automatically controlling the supply of welding gas is shown. This means comprises a globe or other suitable valve 88-which is'mounted on the fixed lower housing 2 of thewelding machine above the draw bench D.

The valve stem 89 of the valve 88 is normally pressed upwardsv by the compressed spring 89?. In this position the globe valve is closed. When the upper housing 1 islowered into operative' relationship with 'the lower housing 2, however, the valve 'stem 89 is forced downwards by a finger 90 fixed to the said upper housing 1 di ctly abovel the said valve stem 89. ,zWhen t e stem 89 is so forced down, the valve 88 is opened, so that as long asthe upper housing 1 remains in operative relationship lwith the' lower housing 2, the supply of welding gas can pass upwards from the auxiliary chamber 85 bythe I pipe 85, and through the valve 88 lto the two pipes' 87 and 87". These pipes lead the welding gas to the edges of the skelped strip as described in connection with the modification illustrated in Fig. 6. l

In Fig. 6, the position of the strip heating furnace" relatively to that of the tube welding machine is shown atX, the reference Y indicating the mouth of the furnace.

By means of the multiple die blockabove described itis ensured that one art of the skelping die is changed automatlcally each time the 'parts of the die are separated and then brought together, whereby the liability of thel die to become choked with scale is entirely obviated and further increase in the output Aof welded tubes per unit of time is effected. j

By means of the automatic control gear hereinbefore described, the supply of welding gas andthe raising and lowering of the upper die member and the upper closing roll are controlled with greater ease and precision than hitherto, whilst it is obvious that the welding operations as a whole may-.be considerably accelerated.

It will be lobvious that many vother constructional modifications may bemade in my invention without departing from the scope thereof and it will' therefore be understood that I do not confine myself tothe constructional forms hereinbefore set forth.

1. For use .in the manufacture of welded machinery comprising closingrolls capa leof relative adjustment towards for awa-v from v one another, means for rotating'the said rolls, .125A a divided Welding die whose parts are separable, means for drawing the Vstrip throu l1 saidfdie and rolls, mechanism operable byt e drawing means and strip whereby the rolls and the parts of the die are simultaneously brought together into operative position or moved apart out of operative position.

2. Tube' weldingv machinery comprisingA closing -rolls capable of relative adjustment said parts areseparated andafterwardstowards or away from one another, means for' rotatinr the said rolls, a divided weldlng die.

whose arts areseparable, means whereby the rolls and the parts of the die can, be simultaneously broughttbgether into operative position or'moved apart outof operative position, and-nieans wherebyone of the parts of the die' is chan ed yautomaticall present a fresh sk e ping surface each time the brought together.

'3.' Tube weldingmachinery comprising.

closing rolls capable of relative adjustment towards or away .from "one another, means for rotating the said rolls, a divided welding '26 .die whose parts -are separable, automatically acting means whereby the rolls and the `parts of the y die are simultaneously brought 'togethei' into operative position and moved apart out of operative position, and means whereby one of the parts of the die is changed automatically lso as to present a fresh skelping'- surface each ltime the said parts are separated and afterwards brought together 4. For use in the manufacture of wel/ded tubes from metal strips, tube welding` machinery, comprising relatively movable closing rolls, means for rotating the'said rolls, a divided'xwelding die whose parts'- are separable means for drawing-thestrip through said die form each side of which block and rolls, trip mechanism operableby the drawing means and strip whereby the rolls and the `parts of the die are simultaneously brought together into operative position or block are adaptedlltobe-raised oit-'lowered sif' multaneously out ofor into operative relationship with .the lower closing roll andv the fixed half die, and means .whereby the halfdie shaped sides of the multiple diefblock are brought successively into operative relationshi automatically by the aforesaid vraising an lowering'offthe upper closing roll and multiple die block. i

6. For use in the *manufacture-'of welded ytubes from metal strips, ltube welding ma chmery comprising superposed closing rolls capable of relative adjustment towards or away from onega'nother, means 'for rotating the rolls,a multiple die block of substantially so as tobonforms .to 'the shape if half of a 'skelping die, a horizontal axis about whichthe multiple die block is turnable, a fixed half-die, .i

s means for` drawing the strip through the fixed half-die and co-operating movable half-die and Vthen through the rolls, mechanism operable by the drawing means and strip whereby the upper closing roll and the multiple die block are adapted to be raised or lowered simultaneously out of or into operative relationship with the lower closing roll and the ixed half die, and means whereby the`halfdie shaped sides of the multiple die block are rotating the'said rolls, a divided welding die whose parts are separable, automatically acting means whereby the rolls and the parts of the die are simultaneously brought together into operative position or moved apart out of operative position and means whereby the Y speedv of separation and approach of the rolls and the parts of the die is graduallyreduced before t ve end of vsaid separation and approach.

8. For use inthe manufacture of welded tubes from metal strips, tube welding machinery comprising .superposed closing rolls capable, of relative 'adjustment towards or away from one another, means for rotating vvthe rolls, a draw'benclr, a'draw bench chain,

means-for operating the chain, an lement on said chain for attachment thereto o .the strip,

a multiple die block ofisubstantially rectangular form each side of which block conforms to the shape of'part of a skelping die, a horizontal axis about which the multiple die block vis turnable, a fixed partial die, mechanism operable by said element on said chain and by saidfstri whereby the upper closing roll and the multlple die block are adapted to be raised or lowered simultaneously out of or into operative relationship withI the lower closing roll and the ixed'par'tial die, means whereby the partial-die shapedfsides of the multiple die block are automatically brought successively into operative relationship with the fixed partial die by the aforesaid raising and lowering of the upper closing rollv and multiple die blbck, and means whereby the speed of raisingI and-lowering the upper roll and the multiple die block is' gradually reduced before the end of said raising and lowering.

9. Tube welding machinery comprisingA closing rolls capable of relative adjustment towards or away from one another, a driving shaft, gearing connecting one of said rolls with said driving shaft, a countershaft, chain and sprocket means connecting the other of rectangular rfo'rmfneach side of which .block said rolls with said counntershafnfchain and 2 sprocket means connecting A'said countershaft and driving shaft so as to keep the closing rolls whether separated or together in consti-Tnt rotation, la divided welding die whose partsfare separable, and automatically acting means whereby the rolls and the parts of the die 'are simultaneously brought together into `operative position or moved apart out of operative position.

10. Tube welding machinery comprising superposed closing rolls capable of relative ad]ustment twards or away from one another, means for rotatingv the rolls, a multiple4 die block of substantially rectangular form each side of which block conforms tothe shape of a skelping die, a horizontal axis about which the multiple die block is turnable, a fixed half die, means whereby the upper closing roll and the multiple die block are adapted to be raised or lowered simultaneously out of or into operative relationship with the lbwer closing roll and the'fixed half n dle, a lever pivotally mounted alongside the multiple die block, a step on the edge of said lever adjacent to the sai-d block, an integral enlargement on the said edge below the said step, pins diagonally arranged on the front of the die block at equal distances from the axis thereof, and means to constrain the said lever constantly towards the' axis of the die block, the arrangement being such that, when 4the upper housing is raised, the said step is projected beneath one of the pins on the block, and, when the upper housing is lowered, the said pin is arrested by the step and the die block is rotated about its axis till the'aforesaid step is retracted automatically by another of the said pins acting on the enlargement of the lever, whereafter the block, having been rotated through a quarter, turn, subsides into contact with the fixed lower halfl of the die.

11. Tube welding machinery comprising superposed closing rolls capable of relative adjustment towards or away from one another, means for rotating the rolls, a divided welding diecomposed ,of separate upper and lower' members, and fluid pressure means vwhereby the upper roll and upper die member are adapted to be raised -or lowered simultaneously, said fluid pressure means comprising an upper ram, a larger lower ram,

' a high pressure fluid supply cond it, an exhaust conduit, means whereby the pper ram is kept in constant communication with thel said high pressure fluid conduit, valve means,

for putting the lower ram into"communica tion with the exhaust conduit or the aforesaid supply conduit, a control 4element for .said valvev means,` and trip means movable with said rams so as automatically to operate said control element so as to Ieffect raising and loweringpofsaid upper roll and upper' `die member by said rams.v

12. Tube welding machinery ofi-fthe type having a draw bench and draw bench chain with means for operating the latter comprising superposed closing rolls capable of relative adjustment towards or away from one another, means for rotating the rolls, a divided welding die composed per and lower members, fluid pressure means whereby the upper roll andthe upper die member are a-dapted to be raised or lowered simultaneously, said fluid pressure means comprising an upper ram, a larger lower ram, a high pressure fluid supplv conduit, an exhaust conduit,means where the upper ram is kept in constant communication with the ,said high pressure fluid conduit, a two way valve disposed in the fluid conduit between the lower ram and the said high pressure and exhaust conduits, trip-gear actuated according to the operation of the draw bench chain so as to control the admission and exhaust of pressure fluid to and from said lower ram* andy means adapted to move with the upper roll and upper die member whereby the opening through said valve, whether opened to exhaust or supply, Ais automatically and progressively reduced to zero atthe end of the stroke of the hydraulic rams.

13. Tube welding machiner comprising superposed closing rolls capab e of relative adjustmenttowards or away. from one another, means for rotating the rolls, a multiple die block of substantially rectangular form, each side of which block conforms to the shape of a skelping die, a horizontal axis about which the multiple die block is turnable, a fixed half-die,"` fluid pressure means whereby the upper closing roll and the multi- .ple die block are a-dapted to be raised or lowyram is. automaticallyput into communica- 'tion with the exhaustconduit or the aforesaid supply conduit 'according as the upper die member and theff roll are to be raised or lowered respectively. l

14. Tube welding `machinery of the type having a draw bench and draw bench chain with means for operating the latter, com'- prising superposed closingl rolls capable of `relative adjustment towards oraway from one another, means for rotiltingv the rolls, a divided welding die ycomposed of separate upper and lower members, fluid pressure of separate upv vio" means whereby, the upper; roll and upper die member are adapted to be raised or lowered simultaneously, said -fluid pressure means comprising an up a high pressure uid suppl haust conduit, -means where conduit, an exv is .kept lin constant, communication with the Isaid high pressure f iuid conduit, a two way valve disposed in the iuid conduit between the lower rain and the said high pressure and exhaust conduits, a cup'on the draw bench chain, a rotatably mounted-crank projecting into the path of the said cup and actuated thereby so as to lower the upper .roll and upper die member, a crank-rotatable with the first mentioned crank and connected to the operating lever of the valve controlling the raising and lowering, a trip lever rotatablel with said cranks, and means whereby the said trip lever can be operated so as to raise the said upper roll and upper die member.

15. For use in the 'manufacture' of welded `tubes from metal str-ips, tube welding machin-.

ery comprising closing rolls capable of relative adjustment towards or awayzirom one another, means for rotating the saidzyrolls,4 a

divided welding die whose parts are separa-- ble, means for drawing the strip through said die and rolls, mechanism operable by the drawing means and .strip whereby the rolls and the parts ofthe die .are simultaneously brought together intol operative positionA or moved apart out of operativeposition, means adapted to supportrhe interior and exterior of the edges o f the skelped strip just before Ait is acted on by the closing rolls, means whereby the edges of the skelped strip are subject- V'edtoa bath of welding gaswhile being supported on the lexterior and interior thereof y the said supporting means, and an auxiliary chamber @for the welding gas, located between the source of supply of the gas and its place of application.

16. Tube weldingvmachinery comprising closing rolls capable of relative 'adjustment towards or away from' one another, means whereby both the closing rolls whether separated or-togetherare kept in constant rotation, a divided welding die whose parts are separable,` means-whereby the rolls and the parts of the die can be simultaneously brought together into operative ositionor moved apart'out of operative position, means whereby one of the parts of the die is changedautomaticallyso as td present a fresh skelping surface each time the' s'aid parts are separated and afterwards brought together, -means ada ted to support the interior and exterior of t e edges ofthe skelped strip just before it is acted on by the closing rolls, means ,whereby the edgesl of the skelped strip are subjected to a bath of welding gasavwhile being su ported on the A'exterior anvd interior thereo by the said supporting means, an auxiliary chamber for the welding gas,loiited the upper rain lbetween the source of supplyiol:l the gas and r ram, a larger lower ram Xautomatically at the separation and bringing together of the parts of the die.

17. Tube welding machinery comprising closing rolls capable of relativeadjustme-nt l towards er away from one another, means for rotating the 'said rolls, a divided welding die whose parts are separable, one lpart being fixedy and the other part rotatable,'means for rotating the'rotatable part.

having a draw bench and draw bench chain with means for operating the latter, comprising closing rolls, amovable h using for one roll, a lixed'housi'ng rfor the-o her roll, a partial die carried by the movable housing, a partial dieonthe ixed housing, means for moving theniovable housing and means controlled by. the presence of a strip in the machine being operated upon for controlling the 'movements of the movable housing.

19. Tube welding machinery comprising closing rolls', a movable housing for one roll, a fixed housing-for the other roll, `a partial die carried bythe movable housing, a partial die on the fixed housing,means for drawing the strip through the completed die and rolls, means vfor moving the movable housing, trip mechanism operablev by the drawing means so i as to cause the las'tgmentioned means to bring said' partial diesl and rolls together, and means 18. Tube welding machinery of the type for automatically causing the trip mechanisml to act-nate the means for' moving the movablehousing to return said partial dies and rolls to separated positionafter the strip has passedtherethrough.-

y 20. Tube welding machinery comprising-a* draw bench and chain, and automatically acting ,means 'controlled by the draw'chain to simultaneously bring together the rolls. and

the parts of the die linto'operative position and controlled bythe passagefof thetube to move 'them apart out of operative position, and means whereby the lsupply of welding j gas is turned ojf and on automatically at the and parts of the die.- 1 21. An apparatus "for skelping and gas .Welding strips into tubes, having a conduit for supplying welding gasto the edges fof the strip, gas controlling means,.means for actuating the gas controlling'means to open separation andibringing together of the rolls ,1.20 l

the gas supply conduit, and means in cooperativerelation with and normally lheld inactive by the strip for 'actuating the gas controlling means to effect closing 'of the gas conduit when the strip passes out of cooperation with said means.v y

22. An apparatus vfor skelping and gas Y welding strips yinto tubes, having a conduit for supplying weldin gas, gas controlling means, means actuate by a moving part of the apparatus for automatically actuating the gas controlling means to openthe gas sup-y ply conduit, a potential device in cooperative relation with the strip and held in a potential condition by the strip while moving through theapparatus, said potential device being associated with the gas controlling means to actuate the same and effect closing of the gas conduit when the strip passes out of cooperation with and releases said potential device.

23. 'An apparatus for skelping strips into tubes, comprising in combination die parts relativelyfmovable towards and away from one another, means forjbringing the die parts together into operative position or for moving them apart out of -operative position, means for energizing the die moving means, a draw 'chain having a trip in cooperative relation .with the energizing means for moving the same to actuate the die moving means to effect closing of the die parts, and potential ,A means held inactive by the strip while pass- I 3o ing through the apparatus for actuating the energizing means to reverse the action of the die moving means and eect separation 'of the die members when the strip passes out of cooperation with said potential means.

In testimony whereof I affix my signature.

. DOUGLAS WHIMSTER CHISHOLM. 

